We present the new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue (~0.44um) and red (~0.64um) band. Accurate starlight subtraction is achieved by referring to all-sky star catalogs and a Galactic stellar population synthesis model down to 32.0mag. We find that the residual light is separated into two components: one component shows a clear correlation with thermal 100um brightness, while another betrays a constant level in the lowest 100um brightness region. The presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, and thus it most likely has the extragalactic origin (i.e., the COB).

Cone search capability for table J/ApJ/736/119/list (List of fits maps)